<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    * {
        margin: 0;
        padding: 0;
    }
    .green {
        background-color: green;
    }
    .orange {
        background-color: orange;
    }
    .clearfix:after {
        content: '';
        display: block;
        clear:both;
    }
    .w150 {
        width: 150px;
        height: 50px;
    }
    .wings main {
        float: left;
        width: 100%;
    }
    .wings .inner {
        margin: 0 150px;
        height: 100px;
    }
    .wings .left {
        margin-left: -100%;
    }
    </style>
</head>
<body>
    <div class="layout">
        <h4>方法二: 双飞翼布局</h4>
        <section class="wings clearfix">
            <main>
                <div class="green inner">inner</div>
            </main>
            <aside class="w150 left orange">
                aside
            </aside>
            <aside class="w150 right orange">
                aside
            </aside>
        </section>
    </div>
</body>
</html>